modified: src/bootloader/bios_functions/bios_disk.asm

	modified:   src/bootloader/bootloader.asm
	new file:   src/include/kernel.h
	modified:   src/include/libc.h
	modified:   src/include/paging.h
	new file:   src/include/panic.h
	modified:   src/kernel/kernel.c
	modified:   src/kernel/libc.c
	modified:   src/kernel/page.c
	new file:   src/kernel/panic.c
	modified:   src/link.ld
	modified:   src/makefile
	modified:   tools/page/page.py

4 files changed, 271 insertions, 56 deletions

diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index d7fc3e0..025dcf3 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -4,14 +4,29 @@
 #include <paging.h>
 #include <video.h>
 #include <acpi.h>
+#include <panic.h>
 
-void panic() { // will fill with debugging info latter
-  printf("Kernel panic!\n");
-  for(;;);
+
+void test4() {
+  char bruh[10];
+  panic(KERNEL_PANIC_KERNEL_RETURNED, KERNEL_PANIC_INVOKED);
+}
+void test3() {
+  char bruh[5];
+  test4();
+}
+void test2() {
+  int a = 1;
+  test3();
+}
+void test1() {
+  printf("fuck\n");
+  test2();
 }
 
 
 void main() {
+  test1();
   if(!(init_serial(COM1))) {
     printf("\nKernal started on CPU 1!\n"); // will detect cpu later
   }
@@ -20,15 +35,16 @@ void main() {
   rsdp = find_RSDP();
   if(!(rsdp)) {
     printf("Couldn't find the RSDP... not sure what to do now.\n");
-    panic();
+    panic(KERNEL_PANIC_RSDP_UNFOUND, KERNEL_PANIC_INVOKED);
   }
 
 
   dump_video();
   debug_print_memory();
 
-  init_memory();
+  init_pmap();
+  debug_pmap();
 
-  panic();
+  panic(KERNEL_PANIC_KERNEL_RETURNED, KERNEL_PANIC_INVOKED);
 
 }
diff --git a/src/kernel/libc.c b/src/kernel/libc.c
index dc5c0ac..c786cd0 100644
--- a/src/kernel/libc.c
+++ b/src/kernel/libc.c
@@ -39,22 +39,33 @@ void strcpy(char *dest, char *src) {
   }
 }
 
-void memcpy(char *dest, char *src, size_t n) {
+void *memcpy(void *dest, char *src, size_t n) {
+  char *p = dest;
   for(unsigned int i = 0; i <= n; i++) {
-    dest[i] = src[i];
+    p[i] = src[i];
   }
+  return(dest);
 }
 
-void bzero(void *dest, size_t size) {
-  unsigned char *p1 = dest;
+void *bzero(void *dest, size_t size) {
+  char *p = dest;
   for(uint64_t i = 0; i < size; i++) {
-    p1[i] = 0;
+    p[i] = 0;
   }
+  return(dest);
 }
 
 //TODO move this function to a seperate math library
-int ceil(float n) {
+unsigned int ceil(double n) {
   int low_n = (int)n;
-  if(n == (float)low_n) return(low_n);
+  if(n == (double)low_n) return(low_n);
   return(low_n + 1);
 }
+
+void *memset(void *s, char c, size_t n) {
+  char *p = s;
+  for(size_t i = 0; i < n; i++) {
+    p[i] = c;
+  }
+  return(s);
+}
diff --git a/src/kernel/page.c b/src/kernel/page.c
index 6f1dd7c..de4f557 100644
--- a/src/kernel/page.c
+++ b/src/kernel/page.c
@@ -2,6 +2,8 @@
 #include <paging.h>
 #include <stdint.h>
 #include <libc.h> 
+#include <limits.h>
+#include <kernel.h>
 
 void debug_print_memory() {
   struct memory_table *memtable = (struct memory_table *)&_meminfo_loc; 
@@ -14,62 +16,194 @@ void debug_print_memory() {
   printf("----------------------------------------------------------------------------\n");
 }
 
+void debug_pmap() {
+  struct phys_map* pmap;
+  int pmap_i = 0, order;
+  uint64_t buddy_size, blong_i, bbit_i, buddy_chunksize, omit_cnt;
+  printf("Maximum buddy order: %u (up to %#x sized chunks)\n", MAX_BUDDY_ORDER, (0x1000 << MAX_BUDDY_ORDER - 1));
+  for(pmap = (struct phys_map*)&_stage2_pagetable; pmap != 0; pmap = pmap->next) {
+    printf("Table %u:\n"
+        "\tPhysical Start:\t%#p\n"
+        "\tTable location:\t%#p\n", pmap_i, pmap->zone_paddr, pmap);
+    for(order = 0; order <= MAX_BUDDY_ORDER - 1; order++) {
+      buddy_chunksize = (0x1000 << order); //TODO just put it in the for loop
+      buddy_size = (((order == MAX_BUDDY_ORDER - 1) 
+          ? (uint64_t *)pmap->next : pmap->buddy[order + 1]) - pmap->buddy[order]);
+      printf("\tbuddy[%u]:\n"
+          "\t\tAddress:\t%#x\n"
+          "\t\tSize:\t\t%u\n"
+          "\t\tBuddies:\t\t\n", order, pmap->buddy[order], buddy_size);
+
+      omit_cnt = 0;
+
+      for(blong_i = 0; blong_i < buddy_size; blong_i++) {
+        for(bbit_i = 0; bbit_i < 64; bbit_i++) {
+          if(*(pmap->buddy[order] + blong_i) & ((uint64_t)1 << bbit_i)) {
+            if((omit_cnt < 20) || (blong_i == buddy_size - 1)) {
+              printf("address %#x\tbit %u: %p\t is free\n",
+                pmap->buddy[order] + blong_i, bbit_i, (uint64_t)pmap->zone_paddr + (((blong_i * 64) + bbit_i) * buddy_chunksize));
+            }
+            omit_cnt++;
+            if(omit_cnt == 20) {
+              printf("\t\t\t[more entries ommited]\n");
+            }
+          }
+        }
+      }
+    }
+    pmap_i++;
+  }
+}
+
+void init_pmap() {
+  struct memory_table *zones = (struct memory_table *)&_meminfo_loc;
+  struct phys_map *pmap = (struct phys_map*)&_stage2_pagetable;
+
+  unsigned int zone_i, pmap_i = 0;
+  int budorder; 
+
+  //we keep this info out of the struct because we won't need it after setting up
+  uint64_t zone_len[MAX_ZONE_CNT], buddy_bitlen[MAX_ZONE_CNT][MAX_BUDDY_ORDER], *buddy_end;
+  uint64_t pmap_size, pmap_bbitsize, pmap_blongsize, buddy_size, buddy_bit, pmap_bit;
+  uint64_t threshold_bitsize, threshold_longsize = 0;
 
-//uses buddy system allocation
-void init_memory() {
-  struct memory_table *memtable = (struct memory_table *)&_meminfo_loc;
-  struct phys_map *map = (struct phys_map*)0x200000;
-  uintptr_t onpage = 0x200000;
-  unsigned int i, x, buddy_size, buddy_bitsize, prev_buddy_bsize;
-  uint64_t *buddy_ptr;
-  
-  map_page((void*)0x200000, (void*)0x200000, PAGE_SIZE_2M);
-  void *next_page = (void *)onpage + 0x200000;
-  // at this point, we are declaring our header and kernel itself as free (so don't forget to fix that!) 
   
-  for(i = 0; memtable[i].length > 0; i++) {
-    if((memtable[i].type == MEM_AVAILABLE) && (memtable[i].ACPI & 1)) {
-     
-      map->chunk_start = (void*)memtable[i].base;
-      map->chunk_size = memtable[i].length;
-      buddy_ptr = (void*)&map->buddies;
+  void *paged_mem = (void *)&_stage2_pagetable + 0x200000;
+  map_page(&_stage2_pagetable, &_stage2_pagetable, PAGE_SIZE_2M);
 
+  for(zone_i = 0; zones[zone_i].length > 0; zone_i++) {
 
-      for(x = 0; x < 8; x++) {
+    if((zones[zone_i].type == MEM_AVAILABLE) && (zones[zone_i].ACPI & 1)) {
 
-        buddy_bitsize = memtable[i].length / (0x1000 * (1 << x));
-        buddy_size = ceil(buddy_bitsize / (float)8);
+      //hopefully this should never happen...
+      //I should dig into the docs to check before removing this.
+      //We also could forget about MAX_ZONE_CNT if we did.
       
-        if((void *)buddy_ptr + buddy_size >= next_page) {
-          map_page(next_page, next_page, PAGE_SIZE_2M);
-          next_page += 0x200000;
-        }
+      if(zone_i >= MAX_ZONE_CNT) {
+        printf("Only %u zones can be used! Modify MAX_ZONE_CNT in paging.h to use all memory.\n", MAX_ZONE_CNT);
+        break;
+      }
 
-        bzero(buddy_ptr, buddy_size); //meant to be /8?
 
-        if((buddy_bitsize * 2) != prev_buddy_bsize) {
-          buddy_ptr[-1] |= (1 << ((prev_buddy_bsize % 8) - 1));
-        }
+      if((zones[zone_i].base <= (void*)&_stage2_pagetable) && 
+          (zones[zone_i].base + zones[zone_i].length >= (void *)&_stage2_pagetable)) { 
+        pmap->zone_paddr = &_stage2_pagetable;
+        zone_len[pmap_i] = zones[zone_i].length - (pmap->zone_paddr - zones[zone_i].base);
+      }
+      else {
+        pmap->zone_paddr = zones[zone_i].base;
+        zone_len[pmap_i] = zones[zone_i].length;
+      }
 
-        buddy_ptr += buddy_size;
+      pmap->buddy[0] = (void *)pmap + sizeof(*pmap);
 
-        prev_buddy_bsize = buddy_bitsize;
+      for(budorder = 1; budorder < MAX_BUDDY_ORDER; budorder++) {
+        buddy_bitlen[pmap_i][budorder - 1] = GET_BUDDY_BITLEN(zone_len[pmap_i], budorder - 1);
+        pmap->buddy[budorder] = (uint64_t *)pmap->buddy[budorder - 1] + 
+          LSIZE_FROM_BITLEN(buddy_bitlen[pmap_i][budorder - 1]);
+      } 
 
-      }
-      map->map_size = buddy_ptr - (uint64_t*)map;
-      map = (struct phys_map *)map + map->map_size;
+      buddy_bitlen[pmap_i][MAX_BUDDY_ORDER - 1] = GET_BUDDY_BITLEN(zone_len[pmap_i], MAX_BUDDY_ORDER - 1);
+      pmap->next = (void *)pmap->buddy[MAX_BUDDY_ORDER - 1] + 
+        (LSIZE_FROM_BITLEN(buddy_bitlen[pmap_i][MAX_BUDDY_ORDER - 1]) * 8);
+
+      pmap = pmap->next;
+      pmap_i++;
 
-      if((void *)map + 24 >= next_page) {
-        map_page(next_page, next_page, PAGE_SIZE_2M);
-        next_page += 0x200000;
+      //allocates by an extra sizeof(struct phys_map),
+      //but were about to discard anyway
+      while((void *)pmap + sizeof(*pmap) >= paged_mem) {
+        map_page(paged_mem, paged_mem, PAGE_SIZE_2M);
+        paged_mem += 0x200000;
       }
-    } 
+
+    }
   }
-}
+  pmap_size = (void*)(pmap) - (void*)&_stage2_pagetable;
+  if(pmap_size >= zone_len[0]) panic(); //TODO debugging
+
+  pmap_i = 0;
+  for(pmap = (struct phys_map*)&_stage2_pagetable; pmap->next != 0; pmap = pmap->next) {
+    for(budorder = MAX_BUDDY_ORDER - 1; budorder >= 0; budorder--) {
+      pmap_bbitsize = ceil((float)pmap_size / ((uint64_t)0x1000 << budorder));
+      pmap_blongsize = pmap_bbitsize / 64;
+
+      if(budorder == MAX_BUDDY_ORDER - 1) {
+        buddy_size = (uint64_t *)pmap->next - pmap->buddy[budorder];
+        buddy_end = (uint64_t *)pmap->next - 1;
+
+        threshold_bitsize = ((pmap_blongsize * 64) + pmap_bbitsize) * 2;
+      }
+      else {
+        buddy_size = pmap->buddy[budorder + 1] - pmap->buddy[budorder];
+        buddy_end = pmap->buddy[budorder + 1] - 1;
+
+        threshold_longsize = threshold_bitsize / 64;
+      }
+      pmap_bit = pmap_bbitsize & 63;
+      buddy_bit = buddy_bitlen[pmap_i][budorder] & 63;
 
-//TODO this function was deleted due to it being wrong. 
-//I'll create it once I have the physical paging prerequisite set up. 
-void create_pagetable_stage2(uint64_t free_mem) {
+
+      if((pmap_bbitsize >= BITLEN_FROM_LSIZE(buddy_size)) && (pmap == (void *)&_stage2_pagetable)) {
+        bzero(pmap->buddy[budorder], buddy_size * 8);
+      }
+      else {
+        if(budorder == MAX_BUDDY_ORDER - 1) {
+          if(pmap == (void*)&_stage2_pagetable) {
+            if(pmap_blongsize) bzero(pmap->buddy[budorder], (pmap_blongsize - 1) * 8);
+            if(pmap_bit) {
+              *(pmap->buddy[budorder] + pmap_blongsize) = ~(((uint64_t)1 << pmap_bit) - 1);
+            }
+            else {
+              *(pmap->buddy[budorder] + pmap_blongsize) = UINT64_MAX;
+            }
+            if(pmap_blongsize + 1 == buddy_size) {
+              *buddy_end &= ((uint64_t)1 << buddy_bit) - 1;
+            }
+            else {
+              memset(pmap->buddy[budorder] + pmap_blongsize + 1, UINT8_MAX, (buddy_size - 1) * 8);
+              if(buddy_bit) {
+                *buddy_end = ((uint64_t)1 << buddy_bit) - 1;
+              }
+              else {
+                *buddy_end = UINT64_MAX;
+              }
+            }
+            threshold_bitsize = ((pmap_blongsize * 64) + pmap_bbitsize) * 2;
+          }
+          else {
+            memset(pmap->buddy[budorder], UINT8_MAX, (buddy_size - 1) * 8);
+            if(buddy_bit) {
+              *buddy_end = ((uint64_t)1 << buddy_bit) - 1;
+            }
+            else {
+              *buddy_end = UINT64_MAX;
+            }
+          }
+        }
+        else if(pmap == (void *)&_stage2_pagetable) {
+          if(threshold_longsize) bzero(pmap->buddy[budorder], (threshold_longsize - 1) * 8);
+
+          if(threshold_bitsize > pmap_bbitsize)
+            *(pmap->buddy[budorder] + threshold_longsize) = ((uint64_t)1 << ((threshold_bitsize - 1) & 63));
+          
+          if(buddy_size - threshold_longsize) 
+            bzero(pmap->buddy[budorder] + threshold_longsize + 1, buddy_size - threshold_longsize);
+          if(buddy_bit & 1) {
+            *buddy_end = ((uint64_t)1 << (buddy_bit - 1));
+          }
+          threshold_bitsize = ((pmap_blongsize * 64) + pmap_bbitsize) * 2;
+        }
+        else {
+          bzero(pmap->buddy[budorder], buddy_size);
+          if(buddy_bit & 1) {
+            *buddy_end = ((uint64_t)1 << ((buddy_bit) - 1));
+          }
+        }
+      }
+    }
+    pmap_i++;
+  }
 }
 
 
@@ -97,7 +231,7 @@ bool map_page(void *virtual_addr, void *physical_addr, uint8_t size) {
     if(table->pml4e[pml4e_i].base_ptr != (uintptr_t)&table->pdpe[pdpe_i] >> 12) goto error;
     if(table->pdpe[pdpe_i].present) {
       if(size == PAGE_SIZE_1G) {
-        if(table->pdpe[pdpe_i].base_ptr == (uintptr_t)pa_ptr >> 30 & 0x1ff)
+        if(table->pdpe[pdpe_i].base_ptr == ((uintptr_t)pa_ptr >> 30 & 0x1ff))
           return true;
         goto error;
       }
@@ -105,7 +239,7 @@ bool map_page(void *virtual_addr, void *physical_addr, uint8_t size) {
 
       if(table->pde[pde_i].present) { 
         if(size == PAGE_SIZE_2M) {
-          if(table->pde[pde_i].base_ptr == (uintptr_t)pa_ptr >> 21 & 0x1ff)
+          if(table->pde[pde_i].base_ptr == ((uintptr_t)pa_ptr >> 21 & 0x1ff))
             return true;
           goto error;
         }
diff --git a/src/kernel/panic.c b/src/kernel/panic.c
new file mode 100644
index 0000000..851684a
--- /dev/null
+++ b/src/kernel/panic.c
@@ -0,0 +1,54 @@
+#include <panic.h>
+#include <stdint.h>
+#include <printf.h>
+
+void panic(int reason, int type) { // will fill with debugging info latter
+  
+  struct stack_frame *frame;
+
+#ifdef EASTEREGG_BLOATWARE
+  printf("Kernel PANIC!!!!!!!\n");
+  printf(
+"     _.-^^---....,,--       \n"
+" _--                  --_  \n"
+"<                        >)\n"
+"|          BOOM           | <------- your computer\n"
+" \\._                   _./  \n"
+"    ```--. . , ; .--'''       \n"
+"          | |   |             \n"
+"       .-=||  | |=-.   \n"
+"       `-=#$%&%$#=-'   \n"
+"          | ;  :|     \n"
+" _____.,-#%&$@%#&#~,._____\n");
+#else
+  printf("Kernel Panic!\n");
+#endif
+
+  printf("Reason:\n");
+
+  switch(reason) {
+  case KERNEL_PANIC_PMAPSIZE :
+    printf("\tThe physical map can't fit in the first memory zone.\n"
+        "\tNote: If you have this issue, please contact me.\n"
+        "\tIt's a fixable bug caused by an unlikely scenario.\n");
+    break;
+  case KERNEL_PANIC_RSDP_UNFOUND:
+    printf("\tRSDP unfound!\n");
+    break;
+  case KERNEL_PANIC_KERNEL_RETURNED:
+    printf("\tThe kernel (almost) reached its return!\n");
+    break;
+  }
+  printf("\nStack trace:\n");
+
+  asm("mov %%rbp,%0" : "=r"(frame) ::);
+
+  for(; frame->next != 0; frame = frame->next) {
+    printf("\t%x\n", frame->function_base);
+  }
+
+  //It's not public yet, but it will be
+  printf("\nAfter ensuring your computer meets the requirements specified, if you think this is a bug, please open an issue on the git repo or email me at %s.\n", DEV_EMAIL);
+  for(;;);
+
+}